That loud boom was, in fact, a sonic boom from a F-15 fighter jet. In a Facebook post, Robins Air Force Base says it happened over Central Georgia at around 3:30 p.m.

Boom Supersonic says the company's XB-1 aircraft achieved supersonic flight without an audible sonic boom on the ground below.

Boom Supersonic also noted this week’s work officially concludes its multiyear flight test program. XB-1 will soon travel from the Mojave Air & Space Port near Barstow, California to its ...